/**
 * <pre>
   Copyright 2016 aaron.sd

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 * </pre>
 * 
 * @author aaronwong.sd@foxmail.com
 * @version 下午8:43:02
 */
package com.iwechat.mp.dobbo.provider.impl;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.stereotype.Component;

import com.iwechat.mp.dobbo.provider.callback.CallbackListener;
import com.iwechat.mp.dobbo.provider.callback.CallbackService;

/**
 * CallbackServiceImpl
 * 
 * @author aaronwong.sd@foxmail.com
 */
@Component("callbackService")
public class CallbackServiceImpl implements CallbackService {
    private final Map<String, CallbackListener> listeners = new ConcurrentHashMap<String, CallbackListener>();

    public CallbackServiceImpl() {
        Thread t = new Thread(new Runnable() {
            public void run() {
                while (true) {
                    try {
                        for (Map.Entry<String, CallbackListener> entry : listeners.entrySet()) {
                            try {
                                entry.getValue().changed(getChanged(entry.getKey()));
                            } catch (Throwable t) {
                                listeners.remove(entry.getKey());
                            }
                        }
                        Thread.sleep(3000); // 定时触发变更通知
                    } catch (Throwable t) { // 防御容错
                        t.printStackTrace();
                    }
                }
            }
        });
        t.setDaemon(true);
        t.start();

    }

    /*
     * (non-Javadoc)
     * 
     * @see com.iwechat.mp.dobbo.provider.callback.CallbackService#addListener(java.lang.String,
     * com.iwechat.mp.dobbo.provider.callback.CallbackListener)
     */
    @Override
    public void addListener(String key, CallbackListener listener) {
        listeners.put(key, listener);
        listener.changed(getChanged(key)); // 发送变更通知
    }

    private String getChanged(String key) {
        return "Changed: " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());
    }

}
